When MySQL is installed on a Vault Server, you may encounter problems using Vault. For example, logging in with the Vault website login page (http://<your Vault server>/vaultservice/vaultweb) will fail. Upon inspection of the Vault Server Log look for errors claiming the Vault Server cannot connect to MySQL.

It appears when MySQL is installed, by default it will install a "Web Providers" component which will override the handling of the "ConnectString" found in EVERY web.config on that IIS Server. This causes an issue since Vault web.config's ConnectString is designed for SQL Server.

Possible Solutions (You should only need to pick one to solve the problem.)

1. Remove the WebProviders component from the MySQL installation or uninstall / reinstall MySQL but use the Custom installation and do not choose the MySQL WebProviders component.

2. Add the following to the web.config within the Vault Server's IIS directory.